Two-End Intimal Flap Suturing Method for Establishing Stanford B Type Aortic Dissection in a Canine Model

Abstract

To establish an animal model of Stanford type B aortic dissection using a two-end intimal flap suturing. Twelve adult mongrel dogs of either sex were studied and followed up, at intervals, up to 1 year. A lateral clamp was placed on the proximal descending aorta after general anaesthesia and left thoracotomy. Half the circumference of the aorta, including the media and adventitia, was cut open transversely, leaving the intima intact. The aortic wall was separated inferiorly. The intima was transversely cut and both ends of the distal intimal flap were sutured to the adjacent aorta. To close, the distal adventitia and media were sutured to the proximal aorta. Before thoracic cavity closure, digital subtraction angiography (DSA) and colour Doppler ultrasound were performed. Formation and distal extension was observed immediately after removal of the partial aortic clamp in 11 dogs. True and false lumens were seen in eight dogs; the false lumen was larger than the true lumen. Sacrifice at set intervals, 7 days to 12 months after surgery, showed a typical dissection tear, intima, septum, adventitia, thrombi and distal dissection blind pocket. This model of aortic dissection using the two-end aortic intimal flap suturing method is similar to human Stanford type B aortic dissection.